<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="../js/jquery.min.js"></script>

</head>

<body>
  <form action="" id="formdata">
    账号<input type="text" name="userName" /><br><br>
    密码<input type="password" name="password" /><br>
    <button type="submit">提交</button>
  </form>
  <script>
    $(() => {
      $('#formdata').on('submit', e => {
        e.preventDefault()
        console.log($('#formdata').serialize())
      })
    })
  </script>
</body>

</html>